Bounded memos and scoped cut

• use a bounded dict for memos
• do not clear memos upon cut
• limit cuts to the closest choice
• use temp directory instead of cwd for test storage (#370
• move GitHub workflow to 3.14
• remove filesystem execute permission from two non-script files (#368)
• set execute bit on two script-like library sources that have shebangs (#369)
• fix non-thread-safe access of globals() (#365)
• [ci] modernize (#359)